This was the first of the Dr. Kildare films to omit Lew Ayres from the cast due to Mr. Ayres declaring himself a conscientious objector at the beginning of WWII. He served with distinction in the medical corps in WWII. Mr. Ayres wasn't opposed to dying for his country, he just didn't want to kill for any reason. Since hysteria can often be the close companion to patriotism in times of national trial, MGM didn't want the negative publicity so Lew Ayres was out. Philip Dorn, here playing psychiatrist Dr. John Hunter Gerniede, seems to be filling in the part of the younger doctor that would have normally been played by Lew Ayres as Dr. Kildare.
Normally these abrupt cast changes in movie franchises lead to inferior films, at least for the first couple of post-transition entries, but here the outcome is quite satisfying and interesting. Dr. Gillespie is brought in to examine a wealthy young man, Roy Todwell, after he abruptly becomes violent after hearing a train whistle - any train whistle. After the violent act he says he remembers nothing. His first violent act is to kill a dog with a rock when his fiancée (Donna Reed as Marcia) refuses to elope with him. Later he smashes up a store. Roy is hospitalized for observation, but soon escapes, believing that Dr. Gillespie wants to commit him to a madhouse, thus he wants to kill Dr. Gillespie and sends him frequent postcards telling him so. Thus the police and Drs Gerneide and Gillespie are trying to locate and capture Roy before his acts rather than his threats turn homicidal.
This is a very good entry in the series with lots of suspense and elements of noir. The actor who plays Roy is particularly effective. He has almost a "howdy-doody" kind of physical presence, barely masculine and hardly menacing yet he has a very cold deliberate stare and facial expression as he goes about wreaking havoc. Nat Pendleton continues in his role as orderly Joe Wayman who has been tasked with guarding Dr. Gillespie without letting Dr. Gillespie know what's going on. In the case of Joe trying to be subtle, comical complications ensue. The case of Roy Todwell carries over into the next entry in the series as well, "Dr. Gillespie's Criminal Case", also worth seeing even without the suave Dr. K.
